A spin transfer torque MRAM (Magnetic Random Access Memory) including a magnetoresistive element containing a ferromagnetic material as a memory element has been proposed (this memory will be called an MRAM hereinafter). This MRAM is a memory that stores information by controlling the electrical resistance of the magnetoresistive element in two states, i.e., a high-resistance state/low-resistance state by changing the magnetization direction in a magnetic layer by an electric current to be injected into the magnetoresistive element.
The magnetoresistive element includes a memory layer as a ferromagnetic layer having a variable magnetization direction, a reference layer as a ferromagnetic layer having an invariable magnetization direction, and a tunnel barrier layer as a nonmagnetic layer formed between them.